At present, the basic working principle of the cross-cut shredders commonly used is that blades combined with spacing rings are mounted on a shaft, and two parallel shafts driven by a motor cooperated with a gear mechanism rotate reversely to form a shearing force to cut papers passing through into thin strips. Please refer to the common shredder blade shown in FIG. 1 and the common shredder blade assembly shown in FIG. 2, and the common shredder blade is made of a metal sheet and molded by mechanical punching through a die to be a circular shredder blade the center of which has a polygonal central hole 1 into which the shaft can insert, and the circumference of which protrudes outwardly to form uniform cutting edges 2, when a blade set H is formed by combining two shredder blades mounted on the shaft F in a back-to-back manner as shown in FIG. 2, the uniform cutting edges of these two shredder blades would assume a V-like knife-edge 3, while on an opposite shaft F′, another blade set H′ is formed by combining two shredder blades spaced by a spacing ring in a face-to-face manner. When papers to be shredded pass through the two reverse rotatory shafts F and F′, the opposing rotation of the blade circumferences, i.e. the blade bodies 4 and 4′, would cut the papers like scissors into strips, and the opposing rotation of the knife-edge 3 and the opposite blade body 4′ then would cut the strips crossly to fragment the strips into chips.
Now the shredder blade used commonly in the common shredders is usually formed integrally by punching a metal sheet having a thickness of more than 1 mm with a die, then a single blade set is 1×2 mm in thickness, which results in the width of the shredded paper obtained is 1×2 mm correspondingly. Because in the shredding process, firstly the blade points of two opposite blade sets penetrate the paper to make holes, then the paper is cut and fragmented into chips (as shown in FIG. 2), due to the width of the cut paper equals to the thickness of the common blade set, and in order to ensure the strength of the shredder blades in the horizontal cutting, the strength of the blade points should be relatively high, the thickness of the shredder blade can not be too thin, otherwise the cutting edge would be deformed and even broken, so the shredder blade is made by punching the relatively thick materials, which makes the high material cost that is unable to adapt to the shredder industry status of the increasingly severe shredder price competition. In addition, for the thickness of the commonly used shredder blades can not be reduced, and the shredder blade is a solid body, its quality is relatively big and needs a relatively high power to drive the two shafts having blade sets to shred papers.
A thin shredder blade is made by punching at the cutting part of a thin metal sheet to form a protrusion 6, which reduces the material cost greatly, while the cutting part (including the blade point 5) has a relatively high strength, but due to the processing method, there is a step between the blade point 5 and the protrusion 6 (as shown in FIG. 3), when two shredder blades AI and BI having blade points with a step form a blade set in a back-to-back manner (as shown in FIGS. 4a and 4b), the knife-edge penetrating the papers is not progressive, as shown by the curve line 7, the resistance force is increased abruptly, and papers are torn off and are not cut like traditional solid shredder blades, and for the two blade points 5 are relatively small, they would break even rupture to be unable to cut the papers in the continuous use, and also the too small blade points 5 would grasp the chips which would then accumulate in the continuous use to increase the resistance force to the motor and break down the blade points 5, thus, the blade point with a step limits the application of this kind of thin shredder blades severely.
In order to solve the existing problems and shortcomings mentioned above, it is necessary to improve the common thin shredder blades.